Jatinderdeep Kaur, Coefficients of Some Double Trigonometric Cosine and Sine Series. journal = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology. October 2015, vol. 107(11). 666 - 669 [viewed 29 March 2024]. Available from: https://publications.waset.org/pdf/10002758.